Experimental and numerical validation of a simplified rigid torso surrogate used for investigating the fluid-structure interaction of air blast waves

Abstract

Blast waves from landmines and Improvised Explosive Devices (IEDs) produce an almost instantaneous rise in pressure which causes Primary Blast Injuries (PBI). The primary blast injuries are caused directly by the blast wave and encompasses injury to air containing organs such as the lung, ear, and bowel. The most notable primary injury is the blast lung, which is a contusion of lungs in which blood contaminates the alveoli leading to death. The PBI criteria are specified in test standards to relate pressure measurements in a testing environment to a risk of PBI. This study examines the adequacy of using a torso surrogate to measuring pressure profiles both experimentally and numerically. A simplified rigid human torso surrogate, referred to as the Blast Test Device (BTD), was manufactured and tested. The BTD comprises a high-density polyethylene (HDPE) cylinder with an outer diameter of 300 mm, height of 802 mm and wall thickness of 20 mm. The BTD was exposed to complex blast waves in free-field conditions, which were created by detonating 300 g Plastic Explosive (PE4) at three different heights above ground over a smooth, concrete surface. The experimental results were compared to the numerical results as well as results available in literature. The experimental results were compared with respect to incident pressures, reflected pressures and positive phase duration of the blast wave. Morphological correlation was observed between the experimental and literature results, however time delays for initial peaks were observed in three of the comparisons. The numerical predictions also compared well morphologically, but with time delays observed for side-on pressures, as well as differences in initial peak pressures.